Analysis Of FGF Receptor Signalling Involved In Lens Cell Proliferation And Differentiation
Funder
National Health and Medical Research Council
Funding Amount
$343,028.00
Summary
Cataract, the loss of transparency of the eye lens, is the leading cause of blindness in the world. An eventual cure for cataract depends on a better understanding of the basic molecular processes in the normal and cataractous lens. Our research has focussed on identifying the molecules that control the formation and maintenance of the lens. Growth factors are important regulators of cell behaviour and our studies have provided compelling evidence that members of the FGF growth factor family pla ....Cataract, the loss of transparency of the eye lens, is the leading cause of blindness in the world. An eventual cure for cataract depends on a better understanding of the basic molecular processes in the normal and cataractous lens. Our research has focussed on identifying the molecules that control the formation and maintenance of the lens. Growth factors are important regulators of cell behaviour and our studies have provided compelling evidence that members of the FGF growth factor family play pivotal roles in lens developmental biology by influencing lens cell proliferation and differentiation. An important finding from our laboratory is that FGF induces lens epithelial cell proliferation and differentiation at different concentrations. The FGFs elicit intracellular responses upon binding to and activating cell surface FGF receptors (FGFRs). The FGFRs are membrane bound tyrosine kinases which upon activation, activate specific signalling pathways leading to a specific cellular response. To understand how FGFs mediate and regulate different responses in lens cells, namely cell proliferation and fibre differentiation, we plan to examine the role of FGFRs in normal lens development using genetically altered FGFRs that will be expressed specifically in lenses of transgenic mice. While it is known that four different FGF receptor genes are expressed by the normal developing lens, it is unknown what role each of these play in the process of lens cell proliferation and differentiation. In addition, as we can reproduce a specific FGF-induced lens cellular response in vitro, we will use our lens explant culture system to dissect the signalling pathway(s) downstream from specific receptor activation and correlate this with a specific cellular response. By identifying the molecules and mechanisms that control the cellular processes essential for normal lens development, we can better understand how disruptions of these processes lead to cataract formation.Read moreRead less
Growth-factor Induced Signalling Pathways Involved In The Regulation Of Lens Cell Behaviour
Funder
National Health and Medical Research Council
Funding Amount
$253,500.00
Summary
Cataract, the loss of transparency of the eye lens, is a major cause of blindness in the world. A cure for cataract depends on a better understanding of the molecular processes in the normal and cataractous lens. Lens growth is regulated by controlled proliferation of epithelial cells and their precise localised differentiation into fibres. As disruption of this tight regulation leads to cataract, identifying the molecules that control cell proliferation and differentiation may provide insights ....Cataract, the loss of transparency of the eye lens, is a major cause of blindness in the world. A cure for cataract depends on a better understanding of the molecular processes in the normal and cataractous lens. Lens growth is regulated by controlled proliferation of epithelial cells and their precise localised differentiation into fibres. As disruption of this tight regulation leads to cataract, identifying the molecules that control cell proliferation and differentiation may provide insights into the mechanisms involved in cataract formation. Following cataract surgery, for example, a number of patients develop aftercataract which results from the response of lens cells remaining after surgery. These residual cells, unlike those tightly regulated in the normal lens, begin to divide and differentiate in an attempt to form a new lens. The main aim of this study is to understand what regulates the proliferation and differentiation of lens cells. Growth factors are key regulators of cell behaviour and our studies provide evidence that members of the FGF, PDGF and IGF growth factor families play pivotal roles in the lens by influencing cell proliferation and differentiation. Growth factors stimulate cellular processes by activating specific cell surface receptors. Once activated, these receptors switch on specific intracellular signalling pathways leading to a specific cellular response. To understand how different growth factors mediate and regulate lens cell proliferation and fibre differentiation, we plan to examine the role of FGF-, PDGF- and IGF-induced signalling in normal lens biology. To do this, we will use a well established lens explant culture system to dissect the signalling pathway(s) downstream of specific receptor activation and correlate this with a specific cellular response. By understanding the cellular processes essential for normal lens development, we can better understand how disruptions of these processes lead to cataract formation.Read moreRead less
Regulation Of Lens Cell Behaviour By RTK Antagonists, Sef And Sprouty.
Funder
National Health and Medical Research Council
Funding Amount
$319,446.00
Summary
Cataract, the loss of transparency of the eye lens, is a major cause of world blindness. A cure for cataract depends on a better understanding of the molecular processes in the normal and cataractous lens. Lens growth is regulated by controlled proliferation of epithelial cells and their localised differentiation into fibres. As disruption to this tight regulation leads to cataract, identifying the molecules that control cell proliferation and differentiation will provide insights into the mecha ....Cataract, the loss of transparency of the eye lens, is a major cause of world blindness. A cure for cataract depends on a better understanding of the molecular processes in the normal and cataractous lens. Lens growth is regulated by controlled proliferation of epithelial cells and their localised differentiation into fibres. As disruption to this tight regulation leads to cataract, identifying the molecules that control cell proliferation and differentiation will provide insights into the mechanisms involved in cataract formation. Following cataract surgery, for example, many patients develop aftercataract which results from residual lens cells. These residual cells, unlike those tightly regulated in the normal lens, divide and differentiate to form a secondary cataract. The main aim of this study is to understand what molecules regulate the proliferation and differentiation of lens cells. Growth factors are key regulators of cell behaviour and our studies provide evidence that FGF growth factors play pivotal roles in the lens by influencing cell proliferation and differentiation. We have recently identified inhibitors of FGF in the lens, called Sprouty and Sef; molecules shown in other systems to effectively block FGF intracellular signalling pathways. To understand how Sef and Sprouty regulate lens cell proliferation and fibre differentiation, we plan to examine what regulates their expression, and more importantly their role in FGF-induced cell signalling in normal lens biology. To do this, we will use a well established explant culture system to monitor the effectiveness of these endogenous inhibitors on growth factor-induced lens cell proliferation and differentiation, as well as use transgenic mice technology to determine the role they play in situ. By understanding the molecular and cellular processes essential for normal lens development, we can better understand how disruptions of these processes lead to cataract formation.Read moreRead less
Roles For MAPK-ERK1-2, -catenin-TCF And Smad3 Mediated Signalling Pathways In TGF -induced Cataract
Funder
National Health and Medical Research Council
Funding Amount
$339,071.00
Summary
Posterior capsular opacification (PCO) is a common and costly complication of cataract surgery that is caused by aberrant growth of lens cells. The TGF growth factor family causes PCO. TGF activates three signalling pathways in the lens, MAPK-ERK1-2, -catenin-TCF and Smad3; however currently we do not know which one induces PCO. This project will identify the pathway(s) that prevent TGF from causing cataracts. This is critical for the development of pharmaceuticals to prevent PCO.
Inductive Interactions Between Lens And Optic Cup Specify Cell Fates
Funder
National Health and Medical Research Council
Funding Amount
$265,500.00
Summary
Normal eye development depends on interactions between embryonic eye tissues. In the front part of the eye inductive interactions between lens and optic vesicle are important for the formation and growth of lens, ciliary body and iris. Our recent studies indicate that a family of developmentally important growth factors, the Wnts, plays key roles in this process. Our proposed studies will examine, for the first time, the role of Wnts in lens, ciliary body and iris development. Specific experimen ....Normal eye development depends on interactions between embryonic eye tissues. In the front part of the eye inductive interactions between lens and optic vesicle are important for the formation and growth of lens, ciliary body and iris. Our recent studies indicate that a family of developmentally important growth factors, the Wnts, plays key roles in this process. Our proposed studies will examine, for the first time, the role of Wnts in lens, ciliary body and iris development. Specific experimental outcomes will show if Wnts are important in promoting the formation and maintenance of the front part of the lens, the lens epithelium. The outcomes will also give us information on the molecules that mediate the effects of Wnts on lens cells and if regulatory factors from the lip of the optic cup-ciliary body can influence the pathways by which Wnts can influence the lens cells. In addition we will learn if lens-derived Wnts have a role in the formation of ciliary body and iris. Identifying factors that regulate the formation of eye tissues is fundamental to understanding the molecular basis of eye disease. For example, cataract is the most common cause of blindness in the world. Cataract surgery is the most common surgical procedure and is placing an ever-increasing burden on health care budgets. Cataracts that most commonly require surgery usually involve abnormal growth and behaviour of lens cells such as occurs in posterior subcapsular cataract and posterior capsular opacification (also known as aftercataract because it occurs subsequently to cataract surgery). Identifying molecules and mechanisms that are involved in normal formation and growth of lens cells is fundamental to understanding these diseases. In addition, as it is well known that the lens is required for the normal formation of the front part of the eye, including the ciliary body and iris, results from this study may also shed light on some developmental abnormalities such as small eye.Read moreRead less